const String LOGIN_USERNAME_PARAM_KEY = 'username';
const String LOGIN_PASSWORD_PARAM_KEY = 'password';
const String REQUEST_HEADER_TOKEN_KEY = 'Token';
const String REQUEST_PARAM_TOKEN_KEY = 'token';
const String REQUEST_HEADER_SERIAL_KEY = 'Serial';
const String REQUEST_HEADER_APP_ID_KEY = 'AppId';
